1. Field of the Invention:
The present invention relates a game system which uses a computer to virtually play games, such as ball games, on a video picture displayed on a screen, with responding to commands supplied from an operator.
2. Description of the Related Art
There has been known a game system which can perform a virtual soccer or other ball game based on images displayed on a video screen. In order to give the displayed image powerfulness and the feeling of being at a live performance, a three-dimensional image is used to represent situations of the play within a limited area centering on the soccer ball, not the entire field where the soccer game is performed.
It is impossible, however, to grasp the locations of all player characters within the whole field by viewing images displaying only the limited area. In addition, deciding strategies, such as passing the ball, is difficult. In order to overcome such difficulties, recent game systems performing the soccer game is designed such that a radar picture (image) is superimposed on a part of the game play picture (image). The radar picture displays a reduced-size image of the entire field, wherein dots corresponding to all players are shown with different colors assigned to two teams confronting each other.
However, the above radar picture constantly displays the entire field regardless of the changes of the game playing situations in the course of the game. Thus, in case that the player characters gather in certain areas of the field in particular occasions, typically, in a battle in a frontal area of a goal or corner kicks in a soccer game, it is difficult to distinguish the players from one another. This leads to such a drawback that the operator cannot quickly recognize the game situations from the displayed images.
Accordingly, it is an object of the present invention to provide a video game system and a storage medium used in the video game system, which enable an operator to obtain appropriate information about the situations of a game from a radar picture timely and steadily.
According to one aspect of the present invention, there is provide a video game system used by an operator to perform a virtual play in which player characters on a virtual field are divided into two teams that compete to handle a ball and to carry the ball into a rival-team goal, the system including: a game progress control unit for repeatedly obtaining instructions inputted by the operator and for sequentially changing a game playing situation of the player characters by repeating calculation necessary for specifying the game playing situation based on the instructions; and a display control unit for displaying, based on a calculated result by the game progress control unit, a play image representing the game playing situation within a restricted area centered on a position of the ball in the field and a radar image representing positions of the player characters in a range of the field wider than a range represented by the play image in a manner reduced by a scale-down rate, wherein the display control unit includes a unit for changing the range represented by the radar image and the scale-down rate of the radar image on the basis of the game playing situation.
In accordance with the above configuration, the range displayed by the radar image and its scale-down rate are changed dependently upon the game playing situation. Hence the radar image can provide appropriate information about the game in the course of the game progress. For example, if the player characters gather into a certain area of the field, the displayed range by the radar image is focused on the certain area and its scale-down rate is decreased. This makes it possible to identify each player character and grasp the positions of the player characters. On the other hand, if the player characters are scattered all over the field, the entire field can be displayed in the radar image at larger scale-down rates, enabling the operator to grasp the situation of the game with a broader view.
In an embodiment, the game playing situation may include at least one of the position of the ball, the positions of the player characters, a behavior of the playing character handling the ball and information identifying the team to which each player character belongs.
The display control unit may include a unit for narrowing the range represented by the radar image and decreasing the scale-down rate when the team in offense carries the ball into a near-goal area set around the rival-team goal in the field. As a result, when the offence team carries the ball near the rival-team goal, the radar image is controlled to minutely display the positions of the player characters near the goal. The operator can therefore recognize the detailed situation near the rival-team goal in a steady fashion.
Further, the display control unit may include a unit for widening the range represented by the radar image and increasing the scale-down rate when the team in offense and the team in defense are turned over after the team in offense carries the ball into the near-goal area of the rival-team field. By this, when the team in defense takes the ball from the rival-team near the goal and starts a counter attack, the radar image displays the positions of player characters with a wider range. The operator can consider the successful strategy from the broader viewpoint with reference to the radar image.
The display control unit may include a unit for displaying the radar image at an area opposite to the rival-team goal displayed in the play image when the team in offense carries the ball into the near-goal area. By this, the radar image is displayed at an area opposite to the goal, upon which the operator""s eyes are turned intensively. Thus the radar image does not become an obstacle to the play image.
The display control unit may include a unit for enlarging the radar image When it narrows the range represented by the radar image. If the ball is carried to a position near the goal, the radar image is displayed with its enlarged size. Thus, in association with focusing of a displayed range by the radar image and its lowered scale-down rate, the game playing situation near the goal is displayed minutely.
The display control unit may include a switching delay unit for holding the narrowed range represented by the radar image and the decreased scale-down rate of the radar image until a predetermined situation is satisfied, even if the ball is returned to outside of the near-goal area after the team in offense carries the ball into the near-goal area. Therefore, in cases where the team in offense handles the ball around the border of the predetermined area near the rival-team goal, even if the ball is put in the near-goal area once, then returned to outside the near-goal area, the narrowed displayed range by the radar image and the decreased scale-down rate thereof are maintained until the predetermined situation is satisfied.
This prevents the frequent radar image switching. The predetermined condition may be satisfied when a predetermined time period has passed after the ball is returned to outside of the near-goal area.
In a preferred embodiment, the virtual play may be a soccer, and the display control unit may include a unit for displaying the play image in which a lateral direction thereof agrees with a goal line direction and for displaying the radar image for a corner kick in which positions of the player characters in a restricted area in front of the rival-team goal are represented with the same display direction as the play image when the corner kick is performed. By this configuration, a situation in which the ball enters from a corner post to the frontal area of the goal is displayed in detail. In agreement with this display, behaviors of many player characters gathering in the frontal area of the goal are steadily and precisely displayed by the radar image.
The display unit may display the radar image in a manner superimposed on the play image. In addition, the game playing situation may include the position of the ball, and the display control unit may control the display unit to display a first type radar image when the position of the ball is in a near goal area, defined from a goal line, in the rival-team field and displays a second type radar image when the position of the ball is out of the near-goal areas of the rival-team field and the operator""s team field, the first type radar image representing the positions of the player characters within a partial area on the field including the rival-team goal, the second type radar image representing the positions of the all player characters within the entire field. By this, the area near the goal is displayed in an enlarged manner by the first type radar image if the team in offense is attacking the rival-team goal. Otherwise, the entire field is shown by the second type radar image to enable the operator to grasp the whole game playing situation.
Further, the first type radar image may be represented at a position on the play image on an opposite side of a position where the rival-team goal is represented in the play image, thereby avoiding the interference of the player characters near the goal by the superimposition of the radar image. The size of the first type radar image on the play image may be larger than the size of the second type radar image.
In a preferred embodiment, the near-goal area includes a rectangular area having a longer side which is the goal line of the field and a shorter side of variable length. Further, the display control unit may extend the length of the shorter side when the team in offense carries the ball into the near-goal area in the rival-team field. By this, the frequent switching of the first and the second type radar images may be avoided.
According to another aspect of the present invention, there is provided a storage medium readable by a computer and into which a program of a video game is recorded, the video game is used by an operator to perform a virtual play in which player characters on a virtual field are divided into two teams that compete to handle a ball and to carry the ball into a rival-team goal, the program executing the steps of: sequentially changing a game playing situation by repeating calculation necessary for specifying the situation with reference to instructions given from the operator; displaying, based on a calculation result by changing step, a play image representing the game playing situation within a restricted area centered on a position of the ball on the field and a radar image representing positions of the player characters in a range wider than a range represented by the play image; and switching the range represented by the radar image and a scale-down rate of the radar image on the basis of the game playing situation.
By making a computer read the program recorded in the above storage medium, it is possible for the video game system to achieve the aforementioned object of the present invention.
In the present invention, the ball is not confined to a sphere-like object like a soccer ball or basketball, and it may include a deformed sphere-like object like a rugby ball, or a non-sphere object like a pack used in an ice hockey game. On one hand, the storage medium may include a variety of types of media into which program data are recordable, for example, an optical or magnet-optical recording medium such as a CD-ROM or DVD-ROM, a magnetic recording medium such as a hard disk or floppy disk, or a semiconductor memory device such as a RAM or ROM.